Preparation method of novel chiral macrocyclic dimer

Abstract

The invention belongs to the chemical field of porphyrin and isoporphyrin dimers, discloses a preparation method of a novel chiral macrocyclic dimer, and aims to solve the problems of complex synthesis, poor selectivity and difficulty in introduction of a chiral unit in the prior art. The method comprises the following two steps: at room temperature, reducing a misplaced tetrapyrrole diacylation raw material by sodium borohydride to obtain an intermediate misplaced tetrapyrrole diol I-1; and carrying out condensation, DDQ oxidation and silica gel column chromatography purification on the intermediate and meso-free tetrapyrrole I-2 at room temperature under a dark condition to obtain two target products which are isomers of each other. The product contains a chiral carbon center, is in an asymmetric configuration, can be used for splitting enantiomers, has adjustable spectral properties, is simple and efficient in synthesis steps, provides a new basis for development of chiral optical materials, and expands the application potential in the fields of catalysis, photoelectric materials and the like.

Description

Technical Field

[0001] This invention relates to the field of porphyrin and isoporphyrin dimer chemistry, specifically to a novel method for preparing low-symmetry chiral macrocyclic dimers. Background Technology

[0002] Porphyrins are conjugated tetrapyrrole macrocyclic compounds widely found in nature, possessing high molar extinction coefficients and excellent metal coordination properties. By altering the parent structure of porphyrins, a series of isoporphyrins can be developed, such as dislocated porphyrins containing dislocated pyrrole units and extended porphyrins containing more pyrrole units. These isoporphyrins can achieve special properties not possessed by conventional porphyrins.

[0003] Porphyrin dimers constructed using porphyrins, isoporphyrins, and other motifs exhibit unique physicochemical properties distinct from their monomers, demonstrating broad application potential in catalysis, optoelectronic materials, magnetic materials, near-infrared dyes, and nonlinear optical materials. When chiral elements are introduced into the dimer structure to form chiral dimers, their asymmetric structure can induce novel optical properties such as circularly polarized luminescence, potentially enabling asymmetric selective catalysis and photoelectric conversion, further expanding the application scenarios of chiral optical materials and devices.

[0004] Existing technologies have significant shortcomings: there is still a lack of effective strategies for constructing chiral heterodimers efficiently. The synthesis of traditional porphyrin dimers mainly involves multi-step oxidative coupling reactions by selecting suitable monomer precursors, which is cumbersome and has poor selectivity. At the same time, traditional porphyrin dimers have high symmetry, making it difficult to introduce chiral units to achieve chirality. Summary of the Invention

[0005] The purpose of this invention is to provide a novel method for preparing chiral macrocyclic dimers, which solves the problems of low construction efficiency, cumbersome synthesis steps, poor selectivity, and difficulty in introducing chiral units in the prior art.

[0006] Novel chiral macrocyclic dimer structure The novel chiral macrocyclic dimer provided by this invention comprises product I and product II, which are isomers of each other, and their structural formulas are as follows: 1. Chiral macrocyclic dimer I: ; 2. Chiral macrocyclic dimer II: ; The preparation method of this novel chiral macrocyclic dimer includes the following steps: S1. Preparation of misaligned tetrapyrrole diol I-1 At room temperature, the misaligned tetrapyrrole diacylated starting material was dissolved in a mixed solution of tetrahydrofuran and methanol, and sodium borohydride was added to carry out a reduction reaction. The molar ratio of misaligned tetrapyrrole diacylated to sodium borohydride was 1:25, and the reaction time was 0.5 to 1 hour.

[0007] After the reaction was completed, water was added to quench the reaction, and the solution was extracted three times with dichloromethane. The organic phase was washed with aqueous solution, dried with anhydrous sodium sulfate, and the solvent was evaporated to obtain misaligned tetrapyrrole diol I-1. This intermediate can be used directly in the next reaction without purification.

[0008] The structural formula of misaligned tetrapyrrole diol I-1 is: ; S2. Condensation and oxidation reaction to prepare the target product Under light-protected conditions at room temperature, the misaligned tetrapyrrole diol I-1 and meso-free tetrapyrrole I-2 obtained in step S1 were dissolved in dichloromethane, and a boron trifluoride diethyl ether solution was added dropwise to carry out a condensation reaction. The molar ratio of misaligned tetrapyrrole diol I-1, meso-free tetrapyrrole I-2, and boron trifluoride diethyl ether solution was 1:1:0.4, and the reaction time was 1.5–2 hours.

[0009] After the condensation reaction is completed, dichloromethane is added for dilution, and then DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) is added for oxidation reaction. The molar ratio of misaligned tetrapyrrolidin I-1 to DDQ is 1:8, and the reaction time is 2-3 hours.

[0010] After the reaction was completed, the product was extracted, washed and dried in sequence, and then purified by silica gel column chromatography (eluent: petroleum ether / dichloromethane = 7 / 1) to obtain target product I, a green solid and target product II, a brownish-green solid.

[0011] The structural formula of the intermediate meso-free tetrapyrrole I-2 is: .

[0012] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves the efficient synthesis of novel chiral macrocyclic dimers through acid-catalyzed [4+4] condensation and oxidative fused-ring reactions. The process is concise and overcomes the problems of cumbersome steps and poor selectivity in traditional methods. Utilizing the high reactivity of dislocated pyrrole units and meso vacancies, further fused-ring formation during oxidation is promoted, successfully constructing novel fused-ring dimer products and enabling effective control of spectral properties. The prepared dimer structure contains a chiral carbon center, exhibiting an asymmetric configuration, and can be efficiently separated into enantiomers by chiral high-performance liquid chromatography, providing a new material basis for the development of chiral optical materials and devices. This method provides an effective route for constructing structurally unique and novel low-symmetry chiral macrocyclic dimers, expanding the application potential of porphyrin and isoporphyrin dimers in catalysis, optoelectronic materials, and other fields. Attached Figure Description

[0013] Figure 1 This is a synthetic route diagram for the novel chiral macrocyclic dimer shown in this invention; Figure 2 The absorption spectra of the novel chiral macrocyclic dimers I and II shown in this invention are shown below. Figure 3 The 1H NMR spectrum (298K) of the chiral macrocyclic dimer I shown in this invention is shown below. Figure 4 The carbon NMR spectrum (298K) of chiral macrocyclic dimer I shown in this invention is shown below. Figure 5 The 1H NMR spectrum (298K) of the chiral macrocyclic dimer II shown in this invention is shown below. Figure 6 The carbon NMR spectrum (298K) of chiral macrocyclic dimer II as shown in this invention; Figure 7 This is a schematic diagram of the single crystal structure of the chiral macrocyclic dimer I shown in this invention; Figure 8 This is the circular dichroism absorption spectrum of the chiral macrocyclic dimer I shown in this invention. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Example 1: Structural confirmation of chiral macrocyclic dimers In this embodiment, the structural formulas of chiral macrocyclic dimer compounds I and II are as follows: 1. Product I: ; 2. Product II: ; Example 2: Preparation of Novel Chiral Macrocyclic Dimers Please see Figure 1-8 The present invention also provides the following technical solution: a method for preparing a novel chiral macrocyclic dimer, wherein the chiral macrocyclic dimer comprises the following steps: 1. Preparation of Displaced Tetrapyrrole Diol I-1 In a 250 mL round-bottom flask, add the misaligned tetrapyrrolidine diacylated starting material (600 mg, 0.50 mmol) and a mixed solution of tetrahydrofuran and methanol (20 / 4 mL (v / v)). Stir at room temperature for 10 minutes, then slowly add sodium borohydride (0.57 g, 15 mmol) in two portions and react for 60 minutes.

[0016] After the reaction of the raw materials was monitored by TLC until complete, the reaction was quenched by adding saturated ammonium chloride aqueous solution, and extracted with dichloromethane (4×20mL). The organic phase was dried with anhydrous sodium sulfate, and the two phases were combined and evaporated at 30°C to obtain yellow oily misaligned tetrapyrrole diol I-1, which can be directly added to the next reaction without purification.

[0017] 2. Preparation of target products I and II Add the misaligned tetrapyrrolidinyl diol I-1 and meso-free tetrapyrrolidinyl raw material I-2 (345 mg, 0.50 mmol) obtained in step 1 to a 1 L round-bottom flask, add dichloromethane (60 mL) to dissolve, stir at room temperature for 15 minutes, then slowly add boron trifluoride diethyl ether solution (25 μL, 0.20 mmol), and stir in the dark for about 2 hours.

[0018] After the reaction of diol raw material I-1 was completed by TLC monitoring, dichloromethane (540 mL) was added for dilution. DDQ (915 mg, 4.03 mmol) in dichloromethane (90 mL) solution was slowly added dropwise under stirring at room temperature. After reacting for 2 h, the mixture was passed through a neutral alumina column to remove highly polar and insoluble impurities, and the solvent was removed by rotary evaporation.

[0019] The crude product was separated by column chromatography using petroleum ether / dichloromethane = 7 / 1 as the eluent to obtain a dark green product I (75 mg, yield 8.4%) and a yellow-green product II (56 mg, yield 6.2%).

[0020] 3. Product characterization data Nuclear magnetic resonance (NMR) spectra (H1N, C1N, and mass spectra) of Product I: 1 HNMR (400MHz, CDCl3, ppm) δ9.46 (d, J=8.4Hz,2H),9.19(s,1H),9.Hz,1H),8.70(d, J =4.6Hz, 1H), 8.61(dd, J =9.7, 4.5Hz, 2H), 8.54(dd, J =11.2,4.6Hz,2H),8.46(s,1H),6.90(dd, J =11.5, 4.6 Hz, 2H), 6.78 (d, J =5.2Hz, 1H), 6.55(d, J =4.6Hz, 1H), 6.39(d, J =3.8Hz, 1H), 6.08(d, J =2.0Hz, 1H), 6.04(d, J =3.8Hz, 1H), -0.88(s, 2H). 13 CNMR (151MHz, CDCl3, ppm) δ166.7,152.4,148.4,146.5(d, 1 J CF =256H Z *), 145.1, 139.7, 137.8 (d, 1 J CF =251H Z *), 137.9, 135.3, 133.3, 130.9, 129.2, 128.9, 128.1, 127.1, 123.7, 122.2, 115.4, 114.1, 110.5, 105.6, 104.1, 103.0, 102.0, 97.3, 94.7, 60.3. (* indicates long-range coupling with fluorine atoms, resulting in lower accuracy). HRMS: m / z [M+H] + , calcd for:C 82 H 20 F 35 N8:1781.1252;found:1781.1268. The structure of I is further demonstrated through a single-crystal structure. Figure 7 Characterization showed that the compound structure was correct.

[0021] Nuclear magnetic resonance (NMR) spectra of product II (H1N, C1N, and mass spectra): 1HNMR(400MHz, CDCl3, ppm) δ14.87(s,1H),11.02(s,1H),9.59(d,J=4.9Hz,1H),8.748.69(m,3H) ,8.58(d,J=4.7Hz,1H),8.54(d,J=4.8Hz,1H),8.43(d,J=4.1Hz,1H),8.14(s,1H),7.32(d,J=4.0 Hz,1H),6.64(q,J=5.1Hz,2H),6.58(d,J=4.8Hz,1H),6.38(d,J=5.0Hz,1H),5.36(d,J=3.8Hz,1 H),5.18(d,J=2.7Hz,1H),-1.27(s,2H).13CNMR(151MHz,CDCl3,ppm)δ165.9,152.2,149.2,148. 0,147.9,145.3(d,1JCF=258HZ*),145.2,144.3,142.8(d,1JCF=231HZ*),140.8,140.5,136.5( d,1JCF=263HZ*),133.6,1327,132.4,131.5,128.9,128.3,126.7(d,1JCF=233HZ*),126.6,126. 4,125.3,124.6,122.4,116.9,114.6,114.2,106.1,103.9,102.6,100.7,99.9,92.3,63.01.(*Indicates long-range coupling with fluorine atoms, low accuracy).HRMS:m / z;[M+H]+,calcdforC82H20F35N8:1781.1252;found:1781.1250.

[0022] 4. Explanation of Spectral Properties Product I exhibits distinct Soret-like absorption peaks at 482 and 600 nm, and a broad Q-band absorption peak at 828 nm, with the absorption band edge extending to 1015 nm. Product II has sharp Soret-like bands at 455 and 608 nm, and a weak and broad Q-band at 730 and 815 nm, with the absorption band edge extending to 955 nm, a blue shift of about 60 nm compared to product I. This is due to the different tandem coupling modes of dislocated pyrrole and meso carbon in the two products, with CN tandem coupling in product II increasing the degree of molecular twist.

[0023] The above embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A novel chiral macrocyclic dimer, characterized in that, This includes chiral macrocyclic dimer I and chiral macrocyclic dimer II, which are isomers of each other, with the following structural formulas: Chiral macrocyclic dimer I: ; Chiral macrocyclic dimer II: .

2. A method for preparing the novel chiral macrocyclic dimer as described in claim 1, characterized in that, Includes the following steps: S1. Preparation of misaligned tetrapyrrole diol I-1: At room temperature, the misaligned tetrapyrrole diacylated raw material is dissolved in a mixed solution of tetrahydrofuran and methanol, sodium borohydride is added for reduction, water is added to quench the reaction after completion, and the mixture is extracted, washed, dried and the solvent is evaporated to obtain misaligned tetrapyrrole diol I-1 without purification. S2. Condensation and oxidation reaction: Under light-protected conditions at room temperature, dissociated tetrapyrrole diol I-1 and meso-free tetrapyrrole I-2 were dissolved in dichloromethane, and boron trifluoride diethyl ether solution was added dropwise for condensation. After the reaction was completed, dichloromethane was added for dilution, and then DDQ was added for oxidation. After extraction, washing, drying and purification, target products I and II were obtained respectively.

3. The preparation method according to claim 2, characterized in that, In step S1, the molar ratio of dissociated tetrapyrrole diacyl to sodium borohydride is 1:25, and the reaction time is 0.5 to 1 hour.

4. The preparation method according to claim 2, characterized in that, In step S1, the specific operations for extraction, washing, and drying are as follows: after the reaction is completed, an aqueous solution is added to quench the reaction, dichloromethane is used for extraction three times, the organic phase is washed with an aqueous solution, and the mixture is dried with anhydrous sodium sulfate.

5. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of misaligned tetrapyrrole diol I-1, meso-free tetrapyrrole I-2, and boron trifluoride diethyl ether solution is 1:1:0.4, and the condensation reaction time is 1.5 to 2 hours.

6. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of misaligned tetrapyrrole diol I-1 to DDQ is 1:8, and the oxidation reaction time is 2-3 hours.

7. The preparation method according to claim 2, characterized in that, In step S2, the purification method is silica gel column chromatography, and the eluent is petroleum ether / dichloromethane = 7 / 1.

8. The preparation method according to claim 2, characterized in that, The DDQ is 2,3-dichloro-5,6-dicyano-1,4-benzoquinone.

9. The preparation method according to claim 2, characterized in that, The structural formula of the misaligned tetrapyrrole diol I-1 is as follows: The structural formula of the meso-free tetrapyrrole I-2 is as follows: 。

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